xref: /freebsd/bin/sh/nodes.c.pat (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 *	@(#)nodes.c.pat	8.2 (Berkeley) 5/4/95
33 */
34
35#include <sys/param.h>
36#include <stdlib.h>
37#include <stddef.h>
38/*
39 * Routine for dealing with parsed shell commands.
40 */
41
42#include "shell.h"
43#include "nodes.h"
44#include "memalloc.h"
45#include "mystring.h"
46
47
48struct nodesize {
49	int     blocksize;	/* size of structures in function */
50	int     stringsize;	/* size of strings in node */
51};
52
53struct nodecopystate {
54	pointer block;		/* block to allocate function from */
55	char   *string;		/* block to allocate strings from */
56};
57
58%SIZES
59
60
61static void calcsize(union node *, struct nodesize *);
62static void sizenodelist(struct nodelist *, struct nodesize *);
63static union node *copynode(union node *, struct nodecopystate *);
64static struct nodelist *copynodelist(struct nodelist *, struct nodecopystate *);
65static char *nodesavestr(const char *, struct nodecopystate *);
66
67
68struct funcdef {
69	unsigned int refcount;
70	union node n;
71};
72
73/*
74 * Make a copy of a parse tree.
75 */
76
77struct funcdef *
78copyfunc(union node *n)
79{
80	struct nodesize sz;
81	struct nodecopystate st;
82	struct funcdef *fn;
83
84	if (n == NULL)
85		return NULL;
86	sz.blocksize = offsetof(struct funcdef, n);
87	sz.stringsize = 0;
88	calcsize(n, &sz);
89	fn = ckmalloc(sz.blocksize + sz.stringsize);
90	fn->refcount = 1;
91	st.block = (char *)fn + offsetof(struct funcdef, n);
92	st.string = (char *)fn + sz.blocksize;
93	copynode(n, &st);
94	return fn;
95}
96
97
98union node *
99getfuncnode(struct funcdef *fn)
100{
101	return fn == NULL ? NULL : &fn->n;
102}
103
104
105static void
106calcsize(union node *n, struct nodesize *result)
107{
108	%CALCSIZE
109}
110
111
112
113static void
114sizenodelist(struct nodelist *lp, struct nodesize *result)
115{
116	while (lp) {
117		result->blocksize += ALIGN(sizeof(struct nodelist));
118		calcsize(lp->n, result);
119		lp = lp->next;
120	}
121}
122
123
124
125static union node *
126copynode(union node *n, struct nodecopystate *state)
127{
128	union node *new;
129
130	%COPY
131	return new;
132}
133
134
135static struct nodelist *
136copynodelist(struct nodelist *lp, struct nodecopystate *state)
137{
138	struct nodelist *start;
139	struct nodelist **lpp;
140
141	lpp = &start;
142	while (lp) {
143		*lpp = state->block;
144		state->block = (char *)state->block +
145		    ALIGN(sizeof(struct nodelist));
146		(*lpp)->n = copynode(lp->n, state);
147		lp = lp->next;
148		lpp = &(*lpp)->next;
149	}
150	*lpp = NULL;
151	return start;
152}
153
154
155
156static char *
157nodesavestr(const char *s, struct nodecopystate *state)
158{
159	const char *p = s;
160	char *q = state->string;
161	char   *rtn = state->string;
162
163	while ((*q++ = *p++) != '\0')
164		continue;
165	state->string = q;
166	return rtn;
167}
168
169
170void
171reffunc(struct funcdef *fn)
172{
173	if (fn)
174		fn->refcount++;
175}
176
177
178/*
179 * Decrement the reference count of a function definition, freeing it
180 * if it falls to 0.
181 */
182
183void
184unreffunc(struct funcdef *fn)
185{
186	if (fn) {
187		fn->refcount--;
188		if (fn->refcount > 0)
189			return;
190		ckfree(fn);
191	}
192}
193